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Endoscopy in congenital tracheal anomalies
Endoscopy in Congenital Tracheal Anomalies By Bruce Benjamin
Sydney, Australia 9 Advances in anesthesia and instrumentation, miniaturization of endoscopes and high quality fibreoptic systems n o w allow safe, detailed and precise endoscopic e x a m i n a t i o n of t h e upper and l o w e r r e s p i r a t o r y t r a c t in neonates as well as older children. W h e n t h e clinical f e a t u r e s and radiographic changes suggest a congenital a b n o r m a l i t y of the tracheobronchial t r e e endoscopic e x a m i n a t i o n can give useful information. W e believe congenital anomalies of t h e trachea, particularly areas of congenital stenosis, are not as u n c o m m o n as has been supposed. It is n o w a practical reality to carefully e v a l u a t e and p h o t o g r a p h i c a l l y d o c u m e n t tracheal conditions such as vascular or o t h e r e x t r i n sic c o m p r e s s i o n , c o n g e n i t a l s t e n o s i s or w e b , t r a c h e o e s o p h a g e a l fistula and its sequelae, tracheomalacia and others. INDEX WORDS: Endoscopy; bronchoscopy.
HE PURPOSE of this paper is to outline the
place of endoscopy in pediatric medicine T and surgery with particular reference to congenital tracheal anomalies and is based on experience at the Royal Alexandra Hospital for Children, Sydney, Australia. Laryngo-broncho-esophagology is an expanding branch of pediatric surgery, especially since the availability of fibreoptic lighting, refinement of high quality optical systems, application of the Hopkins rod telescopes, miniaturization of endoscopic instruments and the improved safety of general anesthesia. 1 Study of the upper and lower respiratory tract requires a multidisciplinary approach involving pediatric clinicians in the fields of surgery, medicine, neonatology, thoracic medicine and surgery, gastroenterology, and anesthesia. CLINICAL FEATURES A N D INVESTIGATIONS
Few of the clinical features or combinations of clinical features in congenital conditions causing From Royal Alexandria Hospital for Children, Sydney, New South Wales, Australia. Presented before the XXV1 Annual International Congress o f the British Association o f Paediatric Surgeons, Marseilles, France, July 17-20, 1979. Address reprint requests to Dr. Bruce Benjamin, 231 Macquarie Street, Sydney. N.S.W. 2000 Australia. 9 1980 by Grune & Stratton, Inc. 164
respiratory Obstruction can be considered diagnostic in themselves and it may be difficult to distinguish pharyngeal and laryngeal disease from tracheal manifestations. It is wrong, without confirmatory proof, to associate stridor, for example, with a specific disease and thus disregard the possiblility of any other congenital laryngeal, pharyngeal or tracheal anomaly. The upper respiratory tract may require investigation from the nasal cavities to the main bronchi. Correlation of evidence from the history and findings on physical examination generally determines the necessity for and extent of further tests and radiologic examination. Anteroposterior chest x-rays are a routine requirement. The examination we have found to be most useful and to give the most consistent results is study of the upper airways including the trachea using a lateral airways xeroradiogram. In selected cases contrast esophagogram, screening x-ray examination of the chest and diaphragm, contrast tracheobronchography and occasionally angiocardiography are helpful. Compterized tomography studies are useful in the assessment of congenital masses in the mediastinum and thoracic cavity. It is, therefore, clear that investigation of the larynx and pharynx alone without examination of the tracheobronchial tree and if necessary the esophagus, must be regarded as an incomplete examination. This applies not only to radiologic investigation but to endoscopic examination as well. Although it may be possible to make a preliminary assessment before direct examination a final and confident diagnosis can only be made by appropriate endoscopic examination, if necessary from the nasal cavities to the main bronchi below. We use the Storz equipment and have found it very satisfactory in design, function and safety. The light source can be used with twin fibreoptic flexible cables making a laryngoscope and a bronchoscope readily available for simultaneous use. The various Storz Hopkins telescopes provide excellent resolution and contrast, wide viewing angle, significantly brighter image, natural colour reproduction and the ability to Journal of Pediatric Surgery, Vol. 15, No. 2 (April), 1980
CONGENITAL TRACHEAL ANOMALIES
allow photography] Color transparency photographs may be obtained using the Storz electronic flash generating equipment with the lightbodied Storz reflex camera and using Kodak Ektachrome 35-mm film with a speed of A.S.A.200. CONGENITAL TRACHEAL ANOMALIES
Beside the classical presentation of tracheoesophageal fistula and esophageal atresia, infants with other congenital tracheal anomalies may present with respiratory obstruction and stridor that may have an inspiratory and/or expiratory component. There may be repeated aspiration, cyanotic attacks, apneic attacks, a barking cough, and sometimes hyperextension of the neck. Repeated, prolonged or atypical croup in older infants may occasionally be the first manifestation of a congenital tracheal anomaly. The tracheal lumen in the neonate can be narrowed by webs, stenoses, weakness of the wall
165
or by compression from outside the trachea itself. 2
Extrinsic Compression An anteroposterior chest x-ray may show compression of the tracheal airway due to a bronchogenic cyst, teratoma, cystic hygroma, hemangioma, or other congenital lesion.
Vascular Anomalies The lateral airways xerogram gives even more information. We see compression of the intrathoracic trachea due to the innominate artery 3'4 quite commonly (Fig. 1). Documentation by endoscopic photography is convincing evidence to offer our colleagues in pediatric medicine and surgery. Operative tracheopexy is indicated with severe, life-threatening tracheal obstruction or where so called "reflex apnea" attacks occur. 5 Similar xerogram appearance of compression of the intrathoracic trachea, this time over a
Fig. 1. Lateral chest x-ray taken during a barium swallow. Compression of the intrathoracic trachea by the innominate artery. The tracheal lumen is reduced to a t r a n s v e r s e slit.
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Fig. 2. Severe compression of the intrathoracic trachea by the anterior arch of a double aortic arch. The residual tracheal lumen has a triangular shape in this case.
longer segment, is seen in double aortic arch (Fig. 2). There is often a characteristic triangular appearance of the trachea endoscopically but in some cases there is compression of the lower trachea and both main bronchi. At esophagoscopy the reason for the consistent posterior indentation in the barium swallow can be confirmed as the posterior ,arch of the aorta. Therefore, with bronchoscopic and esophagoscopic examination the diagnosis of double aortic arch can be made with confidence.
abnormal anatomy is quite variable and in other cases there may be a tracheal bronchus with lower tracheal stenosis correlating the endoscopic and x-ray findings (Fig. 4). Contrast tracheobronchography may be necessary to document the nature and degree of the stenosis of the lower airway. In some cases there may be an associated vascular anomaly such as an aberrant pulmonary artery (pulmonary artery sling) .6
Congenital Tracheobronchial Stenosis
H-Type and Recurrent Tracheoesophageal Fistula
The xerogram may show a normal glottic and subglottic region and narrowing of the trachea below this, due to concentric circular cartilaginous rings that cannot be distended. This is the so called "stove-pipe" trachea (Fig. 3). The
We have seen four cases of an H-type (better called an N-type) tracheoesophageal fistula associated with stenosis of the tracheobronchial tree, among other associated congenital anomalies. For diagnosis of suspected communications
CONGENITAL TRACHEAL ANOMALIES
167
Fig. 3. Congenital tracheal stenosis, xeroradiogram and endoscopic view of the trachea showing the circular, complete tracheal cartilagenous rings.
between the trachea and the esophagus we consider that endoscopic examination under general anaesthetic is more reliable and safer than radiologic examination of the esophagus. 7 Should inhalation of contrast material occur in the X-ray Department facilities for resuscitation are not always readily availableJ On the other hand, endoscopy allows comprehensive evaluation of any other congenital anomalies in the tracheobronchial tree and esophagus to be made. 9 For example, we have seen congenital subglottic stenosis, tracheobronchial stenosis, anomalous vessels, lower esophageal stenosis, gastroesophageal reflux, and various laryngeal anomalies. Endoscopic evaluation in our hands has a higher success rate in the diagnosis of tracheoesophageal fistulae than has contrast x-ray studies and endoscopy will diagnose gastroesophageal reflux with spill-over or the rare case of laryngo-tracheal cleft. The esophageal end of the H-type fistula is a characteristic inverted V-shaped slit orifice (Fig. 5) that is not
easily seen while the tracheal orifice of the fistula is in the midline posteriorly and is best seen with an endoscopic telescope. Positive pressure ventilation of the trachea through the endotracheal tube while saline is instilled into the upper esophagus through the esophagoscope may assist in detection of the tracheoesophageal fistula when bubbles of air can be seen coming from the fistula tract. Endoscopic catheterization of the fistula with a fine catheter facilitates surgical treatment] In the same way a suspected recurrence of a fistula occurring some time after primary repair may be difficult to prove and 1~ is best diagnosed at endoscopy (Fig. 6). The fistula is usually at the site of the original lower pouch fistula. We have invariably seen this pouch varying in length from 2 or 3 mm to 10 or 12 mm in every case of repaired tracheoesophageal fistula. It does not necessarily relate to the surgical technique nor to the individual surgeon performing the repair.
168
BRUCE BENJAMIN
Fig. 4. Congenital stenosis of the trachea and main bronchi with a right tracheal bronchus. Correlation of the radiologic and endoscopic findings.
Tracheoesophageal Fistula and Esophageal Atresia We have recently been evaluating endoscopic examination in newborn babies with esophageal atresia and tracheoesophageal fistula prior to primary repair. Preoperative endoscopic evaluation of the fistula prior to definitive repair shows the exact diagnosis and pathological anatomy (Fig. 7). An upper pouch fistula or a double fistula would be recognized. The state of the tracheobronchial tree can be assessed and tracheomalacia or the presence of an associated anomaly can be noted. The length and health of the upper esophageal pouch is seen. Normally the size and site of the fistula is confirmed and a catheter placed through it to allow easier and quicker identification of the fistula by the surgeon, prior to definitive repair.
Tracheomalacia Tracheomalacia following correction of congenital tracheoesophageal fistula is an important
cause of morbidity and death and is a well defined syndrome 5'11 that requires recognition and appropriate treatment. Tracheomalacia after repair of tracheoesophageal fistula and esophageal atresia is manifested by respiratory difficulty, respiratory obstruction, stridor, retention of secretions, aspiration pneumonia, atelectatic areas, pneumonitis, segmental collapse, a barking cough, attacks of cyanosis, sometimes attacks of "reflex apnea," respiratory arrest and even cardiac arrest. When the clinical features suggest tracheomalacia endoscopy should be carried out to confirm the diagnosis and document the severity. Mild and moderate cases can now be managed operatively but severe cases warrant consideration for the operation of tracheopexy that may be life-saving and will certainly reduce morbidity and simplify management. In a few cases there may be almost total anteroposterior collapse of the trachea with a residual lumen of only 2 or 3 mm. In other cases the situation is complicated by the size and position of the residual pouch on the posterior
CONGENITAL TRACHEAL ANOMALIES
169
Fig. 5. The esophageal aspect of an H-type fistula in t w o patients. On the left the inverted V-shaped opening is difficult to identify and on the right it is unusually easy to identify.
tracheal wall of by gastroesophageat reflux with aspiration that may be compounded by a stricture at the esophageal anastomotic repair site. Primary tracheo-bronchomalacia, due to an inherent weakness of the cartilagenous walls of
Fig. 6. The barium swallow in a child aged 2 yr suggested a recurrent fistula although there w e r e no symptoms. A catheter passed through the residual pouch on t h e posterior tracheal wall (above right) enters t h e esophagus at t h e site of the original anastomosis (below right).
the tracheobronchial tree, is very rare and may be localized or generalized. It is commoner for the condition to be localized and secondary to extrinsic pressure for example due to anomalous i n n o m i n a t e artery, a vascular ring or a bronchogenic cyst. The latter may be suspected from the endoscopic findings of compression of the trachea or one of the bronchi. Although formerly we might have documented this finding with a contrast t r a c h e o b r o n c h o g r a m more recently we have found the computerized tomog-
Fig. 7. A neonate w i t h tracheoesophageal fistula and esophageal atresia, showing t h e appearance of t h e trachea before repair. Gastric juice bubbles up the fistula, contaminates the tracheobronchial tree and causes mucosal inflammation. A catheter passed by the endoscopist allows quick and confident identification of t h e fistula by the surgeon at throacotomy.
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BRUCE BENJAMIN
Fig. 8. Computerized tomographic scan confirming a bronchogenic cyst which compressed the lower trachea and carina.
raphy scan (Fig. 8) a satisfactory method of identifying the size and site of the cyst prior to thoracotomy. DISCUSSION
It may be possible to make a preliminary diagnosis from the clinical and radiologic features but where there is continued respiratory obstruction endoscopic examination is necessary. This examination may need to include the nasal cavities, nasopharynx, pharynx, larynx, tracheobronchial tree, and the esophagus. Appropriate therapy may then be initiated for diseases that in many cases are potentially life-threatening. However, not all congenital lesions of the respiratory tract present at birth and the clinical features do not appear for days, weeks, or even longer. As an example vascular compression of the tracheobronchial tree may present at a few months of age with attacks of recurrent or atypical "croup." It must never be forgotten that many infants with congenial tracheal anomalies have major or minor abnormalities of other parts of the respiratory tract or in other organ systems. The stridor associated with tracheal narrowing, whether due to compression, collapse or stenosis may be inspiratory, expiratory, or both inspiratory and expiratory. Tracheomalacia or tracheal compression may be associated with a "barking" cough, the head and neck may be held in hyperextension and there may be cyanotic attacks or apneic attacks. Apneic attacks associated with innominate artery compression of the trachea or with the tracheomalacia found in tracheoesophageal fistula have been called "re-
flex apnea" attacks. Further, with any congenital tracheal abnormality it is common to find excessive or retained secretions associated with pneumonitis, bronchitis, a persistent cough and recurrent or unresolved "pneumonia." Where the tracheal problem is associated with gastroesophageal reflux and aspiration into the tracheobronchial tree, further investigation will be required. A mediastinal mass may be detected radiologically on chest films, anteroposterior and lateral and will be clearly seen with computerized tomography scanning. The mass may be due to a bronchogenic, enteric or duplication cyst, a neurogenic tumor, a teratoma or other congenital lesion. Endoscopy in congenital tracheal abnormalities may be preoperative (e.g., the assessment of esophageal atresia and tracheoesophageal fistula) or postoperative (e.g., the diagnosis of tracheomalacia associated with tracheoesophageal fistula), but is usually performed as a separate diagnostic procedure. The endoscopic findings may indicate the need for further radiologic investigations. Contrast tracheobronchography will outline the trachea and main bronchi if neither bronchoscopes nor telescopes can pass through the area of stenosis. An angiocardiogram may be necessary to demonstrate the anatomy where there is an abnormality of the great vessels and as stated above, computerized tomography is useful in cysts and solid lesions in the mediastinum. After surgical repair of esophageal atresia and tracheoesophageal fistula symptomatology relating to the airway and to the esophagus often coexist in patients who have tracheomalacia, esophageal anastomotic stricture, esophageal reflux with or without aspiration and recurrent or residual fistula. Endoscopy allows evaluation of the degree and extent of the narrowing of the trachea, dilatation of the esophageal stricture, direct examination and biopsy of esophagitis, and identification of a suspected recurrent fistula. Certain tracheal compressions due to anomalies of the great vessels can be accurately diagnosed by endoscopy. In particular innominate artery compression of the trachea occurs where the otherwise normal innominate artery passes from left to right on the anterior wall. Forward
CONGENITAL TRACHEAL ANOMALIES
171
pressure with the tip of the bronchoscope on this pulsating area causes obliteration of the right radial and temporal pulses. With a vascular ring such as a double aortic arch, the left or anterior arch usually compresses the lower trachea and the orifice of one or both main bronchi. In such a case examination of the esophagus shows the right or posterior arch passing as a transverse pulsatile ridge behind the esophagus.
With the equipment now available endoscopic evaluation has become essential to the pediatric surgeon. Endoscopy of the upper respiratory tract and esophagus in infants should be performed only in pediatric hospitals where all the necessary items of equipment together with experienced anesthetic personnel and fully staffed postoperative and intensive care wards are absolutely essential for patient safety.
REFERENCES
1. Gans SL, Berci G: Advances in endoscopy of infants and children. J Pediatr Surg 6:199-233, 1971 2. Holinger PH, Johnston KC, Schild JA: Congenital anomalies of the tracheobronchial tree and of the esophagus, Pediatr Clin North Am 9:113, 1962 3. Fearon B, Shortreed R: Tracheobronchial compression by congenital cardiovascular anomalies in children. Syndrome of apnea. Ann Otol Rhinol Laryngol 72:949 969, 1963 4. Moes MD, Teruo I, Trus[er GA: Innominate artery compression of the trachea. Arch Oto[aryngol (Chicago) 101:733, 1975 5. Benjamin B, Cohen D, Glasson M: Tracheomalacia in association with congenital tracheoesophageal fistula. Surgery 79:504-508, 1976 6. Cohen SR, Landing BH: Tracheostenosis and bronchial abnormalities associated with pulmonary artery sling. Ann Otol Rhinol Laryngol 85:582-590, 1976
7. Gans SL, Johnson RO: Diagnosis and surgical management of "H4ype" tracheoesophageal fistula in infants and children. J Pediatr Surg 12:233 236, 1977 8. Bedard P, Girvan DP, Shandling B: Congenital H-type tracheo-oesophageal fistula. J Pediatr Surg 9:663-668, 1974 9. Holinger PH, Brown WT, Maurizi DG: Endoscopic aspects of post-surgical management of congenital esophageal atresia and tracheoesophageal fistula. J Thorac Cardiovasc Surg 49:22 30, 1965 10. Kafrouni G, Baick CH, Wooley MM: Recurrent tracheoesophageal fistula. A diagnostic problem. Surgery 68:889, 1970 11. Gans SL, Berci G: Inside tracheoesophageal fistula: New endoscopic approaches. J Pediatr Snrg 8:205-211, 1973
Sydney, Australia 9 Advances in anesthesia and instrumentation, miniaturization of endoscopes and high quality fibreoptic systems n o w allow safe, detailed and precise endoscopic e x a m i n a t i o n of t h e upper and l o w e r r e s p i r a t o r y t r a c t in neonates as well as older children. W h e n t h e clinical f e a t u r e s and radiographic changes suggest a congenital a b n o r m a l i t y of the tracheobronchial t r e e endoscopic e x a m i n a t i o n can give useful information. W e believe congenital anomalies of t h e trachea, particularly areas of congenital stenosis, are not as u n c o m m o n as has been supposed. It is n o w a practical reality to carefully e v a l u a t e and p h o t o g r a p h i c a l l y d o c u m e n t tracheal conditions such as vascular or o t h e r e x t r i n sic c o m p r e s s i o n , c o n g e n i t a l s t e n o s i s or w e b , t r a c h e o e s o p h a g e a l fistula and its sequelae, tracheomalacia and others. INDEX WORDS: Endoscopy; bronchoscopy.
HE PURPOSE of this paper is to outline the
place of endoscopy in pediatric medicine T and surgery with particular reference to congenital tracheal anomalies and is based on experience at the Royal Alexandra Hospital for Children, Sydney, Australia. Laryngo-broncho-esophagology is an expanding branch of pediatric surgery, especially since the availability of fibreoptic lighting, refinement of high quality optical systems, application of the Hopkins rod telescopes, miniaturization of endoscopic instruments and the improved safety of general anesthesia. 1 Study of the upper and lower respiratory tract requires a multidisciplinary approach involving pediatric clinicians in the fields of surgery, medicine, neonatology, thoracic medicine and surgery, gastroenterology, and anesthesia. CLINICAL FEATURES A N D INVESTIGATIONS
Few of the clinical features or combinations of clinical features in congenital conditions causing From Royal Alexandria Hospital for Children, Sydney, New South Wales, Australia. Presented before the XXV1 Annual International Congress o f the British Association o f Paediatric Surgeons, Marseilles, France, July 17-20, 1979. Address reprint requests to Dr. Bruce Benjamin, 231 Macquarie Street, Sydney. N.S.W. 2000 Australia. 9 1980 by Grune & Stratton, Inc. 164
respiratory Obstruction can be considered diagnostic in themselves and it may be difficult to distinguish pharyngeal and laryngeal disease from tracheal manifestations. It is wrong, without confirmatory proof, to associate stridor, for example, with a specific disease and thus disregard the possiblility of any other congenital laryngeal, pharyngeal or tracheal anomaly. The upper respiratory tract may require investigation from the nasal cavities to the main bronchi. Correlation of evidence from the history and findings on physical examination generally determines the necessity for and extent of further tests and radiologic examination. Anteroposterior chest x-rays are a routine requirement. The examination we have found to be most useful and to give the most consistent results is study of the upper airways including the trachea using a lateral airways xeroradiogram. In selected cases contrast esophagogram, screening x-ray examination of the chest and diaphragm, contrast tracheobronchography and occasionally angiocardiography are helpful. Compterized tomography studies are useful in the assessment of congenital masses in the mediastinum and thoracic cavity. It is, therefore, clear that investigation of the larynx and pharynx alone without examination of the tracheobronchial tree and if necessary the esophagus, must be regarded as an incomplete examination. This applies not only to radiologic investigation but to endoscopic examination as well. Although it may be possible to make a preliminary assessment before direct examination a final and confident diagnosis can only be made by appropriate endoscopic examination, if necessary from the nasal cavities to the main bronchi below. We use the Storz equipment and have found it very satisfactory in design, function and safety. The light source can be used with twin fibreoptic flexible cables making a laryngoscope and a bronchoscope readily available for simultaneous use. The various Storz Hopkins telescopes provide excellent resolution and contrast, wide viewing angle, significantly brighter image, natural colour reproduction and the ability to Journal of Pediatric Surgery, Vol. 15, No. 2 (April), 1980
CONGENITAL TRACHEAL ANOMALIES
allow photography] Color transparency photographs may be obtained using the Storz electronic flash generating equipment with the lightbodied Storz reflex camera and using Kodak Ektachrome 35-mm film with a speed of A.S.A.200. CONGENITAL TRACHEAL ANOMALIES
Beside the classical presentation of tracheoesophageal fistula and esophageal atresia, infants with other congenital tracheal anomalies may present with respiratory obstruction and stridor that may have an inspiratory and/or expiratory component. There may be repeated aspiration, cyanotic attacks, apneic attacks, a barking cough, and sometimes hyperextension of the neck. Repeated, prolonged or atypical croup in older infants may occasionally be the first manifestation of a congenital tracheal anomaly. The tracheal lumen in the neonate can be narrowed by webs, stenoses, weakness of the wall
165
or by compression from outside the trachea itself. 2
Extrinsic Compression An anteroposterior chest x-ray may show compression of the tracheal airway due to a bronchogenic cyst, teratoma, cystic hygroma, hemangioma, or other congenital lesion.
Vascular Anomalies The lateral airways xerogram gives even more information. We see compression of the intrathoracic trachea due to the innominate artery 3'4 quite commonly (Fig. 1). Documentation by endoscopic photography is convincing evidence to offer our colleagues in pediatric medicine and surgery. Operative tracheopexy is indicated with severe, life-threatening tracheal obstruction or where so called "reflex apnea" attacks occur. 5 Similar xerogram appearance of compression of the intrathoracic trachea, this time over a
Fig. 1. Lateral chest x-ray taken during a barium swallow. Compression of the intrathoracic trachea by the innominate artery. The tracheal lumen is reduced to a t r a n s v e r s e slit.
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BRUCEBENJAMIN
Fig. 2. Severe compression of the intrathoracic trachea by the anterior arch of a double aortic arch. The residual tracheal lumen has a triangular shape in this case.
longer segment, is seen in double aortic arch (Fig. 2). There is often a characteristic triangular appearance of the trachea endoscopically but in some cases there is compression of the lower trachea and both main bronchi. At esophagoscopy the reason for the consistent posterior indentation in the barium swallow can be confirmed as the posterior ,arch of the aorta. Therefore, with bronchoscopic and esophagoscopic examination the diagnosis of double aortic arch can be made with confidence.
abnormal anatomy is quite variable and in other cases there may be a tracheal bronchus with lower tracheal stenosis correlating the endoscopic and x-ray findings (Fig. 4). Contrast tracheobronchography may be necessary to document the nature and degree of the stenosis of the lower airway. In some cases there may be an associated vascular anomaly such as an aberrant pulmonary artery (pulmonary artery sling) .6
Congenital Tracheobronchial Stenosis
H-Type and Recurrent Tracheoesophageal Fistula
The xerogram may show a normal glottic and subglottic region and narrowing of the trachea below this, due to concentric circular cartilaginous rings that cannot be distended. This is the so called "stove-pipe" trachea (Fig. 3). The
We have seen four cases of an H-type (better called an N-type) tracheoesophageal fistula associated with stenosis of the tracheobronchial tree, among other associated congenital anomalies. For diagnosis of suspected communications
CONGENITAL TRACHEAL ANOMALIES
167
Fig. 3. Congenital tracheal stenosis, xeroradiogram and endoscopic view of the trachea showing the circular, complete tracheal cartilagenous rings.
between the trachea and the esophagus we consider that endoscopic examination under general anaesthetic is more reliable and safer than radiologic examination of the esophagus. 7 Should inhalation of contrast material occur in the X-ray Department facilities for resuscitation are not always readily availableJ On the other hand, endoscopy allows comprehensive evaluation of any other congenital anomalies in the tracheobronchial tree and esophagus to be made. 9 For example, we have seen congenital subglottic stenosis, tracheobronchial stenosis, anomalous vessels, lower esophageal stenosis, gastroesophageal reflux, and various laryngeal anomalies. Endoscopic evaluation in our hands has a higher success rate in the diagnosis of tracheoesophageal fistulae than has contrast x-ray studies and endoscopy will diagnose gastroesophageal reflux with spill-over or the rare case of laryngo-tracheal cleft. The esophageal end of the H-type fistula is a characteristic inverted V-shaped slit orifice (Fig. 5) that is not
easily seen while the tracheal orifice of the fistula is in the midline posteriorly and is best seen with an endoscopic telescope. Positive pressure ventilation of the trachea through the endotracheal tube while saline is instilled into the upper esophagus through the esophagoscope may assist in detection of the tracheoesophageal fistula when bubbles of air can be seen coming from the fistula tract. Endoscopic catheterization of the fistula with a fine catheter facilitates surgical treatment] In the same way a suspected recurrence of a fistula occurring some time after primary repair may be difficult to prove and 1~ is best diagnosed at endoscopy (Fig. 6). The fistula is usually at the site of the original lower pouch fistula. We have invariably seen this pouch varying in length from 2 or 3 mm to 10 or 12 mm in every case of repaired tracheoesophageal fistula. It does not necessarily relate to the surgical technique nor to the individual surgeon performing the repair.
168
BRUCE BENJAMIN
Fig. 4. Congenital stenosis of the trachea and main bronchi with a right tracheal bronchus. Correlation of the radiologic and endoscopic findings.
Tracheoesophageal Fistula and Esophageal Atresia We have recently been evaluating endoscopic examination in newborn babies with esophageal atresia and tracheoesophageal fistula prior to primary repair. Preoperative endoscopic evaluation of the fistula prior to definitive repair shows the exact diagnosis and pathological anatomy (Fig. 7). An upper pouch fistula or a double fistula would be recognized. The state of the tracheobronchial tree can be assessed and tracheomalacia or the presence of an associated anomaly can be noted. The length and health of the upper esophageal pouch is seen. Normally the size and site of the fistula is confirmed and a catheter placed through it to allow easier and quicker identification of the fistula by the surgeon, prior to definitive repair.
Tracheomalacia Tracheomalacia following correction of congenital tracheoesophageal fistula is an important
cause of morbidity and death and is a well defined syndrome 5'11 that requires recognition and appropriate treatment. Tracheomalacia after repair of tracheoesophageal fistula and esophageal atresia is manifested by respiratory difficulty, respiratory obstruction, stridor, retention of secretions, aspiration pneumonia, atelectatic areas, pneumonitis, segmental collapse, a barking cough, attacks of cyanosis, sometimes attacks of "reflex apnea," respiratory arrest and even cardiac arrest. When the clinical features suggest tracheomalacia endoscopy should be carried out to confirm the diagnosis and document the severity. Mild and moderate cases can now be managed operatively but severe cases warrant consideration for the operation of tracheopexy that may be life-saving and will certainly reduce morbidity and simplify management. In a few cases there may be almost total anteroposterior collapse of the trachea with a residual lumen of only 2 or 3 mm. In other cases the situation is complicated by the size and position of the residual pouch on the posterior
CONGENITAL TRACHEAL ANOMALIES
169
Fig. 5. The esophageal aspect of an H-type fistula in t w o patients. On the left the inverted V-shaped opening is difficult to identify and on the right it is unusually easy to identify.
tracheal wall of by gastroesophageat reflux with aspiration that may be compounded by a stricture at the esophageal anastomotic repair site. Primary tracheo-bronchomalacia, due to an inherent weakness of the cartilagenous walls of
Fig. 6. The barium swallow in a child aged 2 yr suggested a recurrent fistula although there w e r e no symptoms. A catheter passed through the residual pouch on t h e posterior tracheal wall (above right) enters t h e esophagus at t h e site of the original anastomosis (below right).
the tracheobronchial tree, is very rare and may be localized or generalized. It is commoner for the condition to be localized and secondary to extrinsic pressure for example due to anomalous i n n o m i n a t e artery, a vascular ring or a bronchogenic cyst. The latter may be suspected from the endoscopic findings of compression of the trachea or one of the bronchi. Although formerly we might have documented this finding with a contrast t r a c h e o b r o n c h o g r a m more recently we have found the computerized tomog-
Fig. 7. A neonate w i t h tracheoesophageal fistula and esophageal atresia, showing t h e appearance of t h e trachea before repair. Gastric juice bubbles up the fistula, contaminates the tracheobronchial tree and causes mucosal inflammation. A catheter passed by the endoscopist allows quick and confident identification of t h e fistula by the surgeon at throacotomy.
170
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Fig. 8. Computerized tomographic scan confirming a bronchogenic cyst which compressed the lower trachea and carina.
raphy scan (Fig. 8) a satisfactory method of identifying the size and site of the cyst prior to thoracotomy. DISCUSSION
It may be possible to make a preliminary diagnosis from the clinical and radiologic features but where there is continued respiratory obstruction endoscopic examination is necessary. This examination may need to include the nasal cavities, nasopharynx, pharynx, larynx, tracheobronchial tree, and the esophagus. Appropriate therapy may then be initiated for diseases that in many cases are potentially life-threatening. However, not all congenital lesions of the respiratory tract present at birth and the clinical features do not appear for days, weeks, or even longer. As an example vascular compression of the tracheobronchial tree may present at a few months of age with attacks of recurrent or atypical "croup." It must never be forgotten that many infants with congenial tracheal anomalies have major or minor abnormalities of other parts of the respiratory tract or in other organ systems. The stridor associated with tracheal narrowing, whether due to compression, collapse or stenosis may be inspiratory, expiratory, or both inspiratory and expiratory. Tracheomalacia or tracheal compression may be associated with a "barking" cough, the head and neck may be held in hyperextension and there may be cyanotic attacks or apneic attacks. Apneic attacks associated with innominate artery compression of the trachea or with the tracheomalacia found in tracheoesophageal fistula have been called "re-
flex apnea" attacks. Further, with any congenital tracheal abnormality it is common to find excessive or retained secretions associated with pneumonitis, bronchitis, a persistent cough and recurrent or unresolved "pneumonia." Where the tracheal problem is associated with gastroesophageal reflux and aspiration into the tracheobronchial tree, further investigation will be required. A mediastinal mass may be detected radiologically on chest films, anteroposterior and lateral and will be clearly seen with computerized tomography scanning. The mass may be due to a bronchogenic, enteric or duplication cyst, a neurogenic tumor, a teratoma or other congenital lesion. Endoscopy in congenital tracheal abnormalities may be preoperative (e.g., the assessment of esophageal atresia and tracheoesophageal fistula) or postoperative (e.g., the diagnosis of tracheomalacia associated with tracheoesophageal fistula), but is usually performed as a separate diagnostic procedure. The endoscopic findings may indicate the need for further radiologic investigations. Contrast tracheobronchography will outline the trachea and main bronchi if neither bronchoscopes nor telescopes can pass through the area of stenosis. An angiocardiogram may be necessary to demonstrate the anatomy where there is an abnormality of the great vessels and as stated above, computerized tomography is useful in cysts and solid lesions in the mediastinum. After surgical repair of esophageal atresia and tracheoesophageal fistula symptomatology relating to the airway and to the esophagus often coexist in patients who have tracheomalacia, esophageal anastomotic stricture, esophageal reflux with or without aspiration and recurrent or residual fistula. Endoscopy allows evaluation of the degree and extent of the narrowing of the trachea, dilatation of the esophageal stricture, direct examination and biopsy of esophagitis, and identification of a suspected recurrent fistula. Certain tracheal compressions due to anomalies of the great vessels can be accurately diagnosed by endoscopy. In particular innominate artery compression of the trachea occurs where the otherwise normal innominate artery passes from left to right on the anterior wall. Forward
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pressure with the tip of the bronchoscope on this pulsating area causes obliteration of the right radial and temporal pulses. With a vascular ring such as a double aortic arch, the left or anterior arch usually compresses the lower trachea and the orifice of one or both main bronchi. In such a case examination of the esophagus shows the right or posterior arch passing as a transverse pulsatile ridge behind the esophagus.
With the equipment now available endoscopic evaluation has become essential to the pediatric surgeon. Endoscopy of the upper respiratory tract and esophagus in infants should be performed only in pediatric hospitals where all the necessary items of equipment together with experienced anesthetic personnel and fully staffed postoperative and intensive care wards are absolutely essential for patient safety.
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